What type of purification and quality control methods does BioSynthesis provide for RNA synthesis?

Purification and Q.C Packages

Using a new synthesis technology, Bio-Synthesis is able to meet our customer requirements for high quality DNA, RNA, LNA, BNA oligonucleotides from µg to multi-gram quantities, from research grade to pre-clinical, diagnostic or therapeutic studies. At Bio-Synthesis, DNA, RNA, LNA, BNA and other base analogs can be synthesized at µg to multi-gram quantities while maintaining our commitment for quality. For quality control all our products are analyzed by PAGE, HPLC and mass spectrometry. However, turnaround time may variy based on sequence, purification and quantities requested. It is always advisable to order your reagents well in advance to ensure that you receive the products prior to starting your studies.


For large-scale synthesis dedicated equipment will be used for the synthesis of gram quantity oligonucleotide (under 25 mer) per each lot. All products are provided with their original lot numbers and are under strict quality and lot control.


Several types of purification methods are available

Standard Purification

Salt content is as important as purity in large-scale synthesis. This is the reason for choosing RP-Cartridges and desalting as a default purification methods for this service.

HPLC Purification

  • HPLC is well suited for the purification of modified oligonucleotides as well as unmodified oligonucleotides containing sequences up to 60 bases in length. This is the method of choice to purified larger amounts of oligoucleotides (i.e. > 1 µmol). Purity of > 85% is guaranteed for oligos up to 40 bases.

  • Ion-exchange HPLC (IE-HPLC) is available for the purification of long oligonucleotides up to 60 bases. Anion-exchange resins enable the separation of oligonucleotides on the basis of their charge. The resolution of this technique is very high but their use is limited to purification of rather short oligos. For unmodified oligos between 11-40, purity of > 90% is guaranteed.

  • Dual HPLC Purification and Dual PAGE and HPLC Purification: A combined purification approach is applied for this service: HPLC + IEX HPLC purifications for 20 - 30mers oligos, and HPLC + PAGE purifications for 31 - 50mers oligos. These tandem purifications enable the purification of synthetic oligonucleotides with an average purity of 98% or greater by separating away the majority of base defective products as well as other impurities.

  • RNAase Free HPLC Purification: Originally developed to allow the isolation of RNA oligonucleotides RNase-Free HPLC purification methods have been also used to purify DNA oligonucleotides, especially used when a product free of ribonucleases is needed. RNase-Free HPLC purification is carefully performed in an RNase-free environment. All reagents, equipment and lab surfaces are routinely monitored for RNase contamination.

In Vivo-Ready Purification

Bio-synthesis's In Vivo-Ready purification option provides high quality oligos that are ready for introduction into animals. Each oligo is HPLC purified, dialyzed to ensure that the oligonucleotide is salt free (conductance of <1 microsiemens for a 50 µM solution), sterile filtered, and endotoxin tested. Of course, all oligonucleotides are been analyzed by MALDI-TOF mass spectrometry and analytical HPLC, and sequencing.

Quality Control

Several types of quality control are available

Standard QC package

Analytical anion-exchange HPLC  of oligonucleotide; purity guarantee above 85% in case purification is acquired.

TOF/MS for oligonucleotide identification.

Advanced QC package

  • Standard QC package plus additionally:

  • Ion-pair reverse phase HPLC of the oligonucletoide at 60 oC, purity guarantee above 85%

  • analytical reverse phase HPLC

  • Endotoxin analysis of the oligonucleotide (*phosphorothioates may inhibit in the mechanism for endotoxin determinations Bio-Synthesis is using and therefore reading might be less accurate for these molecules)

  • pH determination of a 1% oligonucleotide solution.

Custom QC Package:

Custom QC package such as:

  • Determination of the sodium content of the oligonucleotide (minimum 20 mg of purified oligonucleotide is required).

  • LC-MS of the oligonucleotides

  • Any custom quality control methods could be developed.

BSI's technical service staff will respond to all your various advices and requests.

BSI's manufacturing line is compliant with GMP.

Allowing the production of reliable products synthezised in our manufacturing line compliant with GMP
(Good Manufacturing Practice).

BSI's supports your R&D with high quality products.